Thermostat



A. J. OTTO ET AL THERMOSTAT Filed Oct. 51 1925 July 8 1924.

8 E f 9 f 3 2. M 9N u 0 ii-Mmmm Patented Julys, 1924.

UNITED STATES PATENT Immun I. orro AND om a. orro, or MILWAUKEE, wIscoNsIN, assmnoasgo :romwsoN sEnvIcI. comm, or MILWAUKEE, wIscoNsIN, A conrona'rrongor WISCONSIN.

THERMOSTAT.

Application led October 81, 1923. Serial No. 671,936.

To all whom z'tmay concern:

Be it known that we,`AR'rHUR J. O'rro and CARL A. Orro, citizens of the United States, residing at Milwaukee, in the county of Mil- I waukee and State of Wisconsin, have invented certain new and useful' Improvements in Thermostats, of which the following -is a specification.

The present invention relates to automatic control of -atmospheric conditions such as temperature humidity and the like, and resides in certain structural improvements in automatic control devices of the pressure operated relay type.

The object of the invention is to produce a device in which the controlled pressure equals or approximates the pressure acting in the relay motor. In most prior devices the contmlled pressure has generally been less than the relay motor pressure by an amount dependent upon the strength of the valve spring or This difficulty can be overcome by e use of a differential diaphragm structure, but such prior structures, so far as we are aware, have been complicated, have commonly required the use of leather or fabric diaphragm, and have been diicult to dismount for cleaning or repair. The present invention rovides a device of this character having a dierential diaphragm control and capable of being readily dismounted for inspection, cleaning or repair.

An important feature of the invention is that a single valve member serves both as the inlet and the exhaust valve for the controlled chamber.

In the drawings:

Fig. 1 is a section of the device on the line 1-1 of Fig. 2; and

4 Fig. 2 is a front elevation of the device with certain parts broken away to show the l'tS. PoThe body of the device is illustrated at 5 and is intended to be mounted on the usual pipe head, not shown, by which the usual connections to the supply and controltpiping are made. Pressure fluid is supplie from the pipe head to the recess 6 and from this recess iiows through the ports 7 and 8. A

second recess 9 is connected by the pipe head and its connected piping with tha-damper motor or valve to be controlled. Y

Formed in the front face of the body 5` is a recess or chamber 10 whose forwardsid'e is covered by a diaphragm 11 shown as composed of metal, with annular corrugations. The diaphragm 11 is apertured at its center to receive a fitting `l2 which is held byl a nutl 13 threaded thereon, and which is rovided with an axial aperture 14, which ranches and opens into the space forward of the diaphragm 11.

This diaphragm is held in place by a metal clamping ring 15 which, in turn, supports va second metal diaphragm 16. The diaphragm 16 is essentially the same as the diaphragm 11, except that it is larger, the ring 15 being shouldered, as shown, to increase the eilr'ective area of the diaphragm 16 relatively to the diaphragm 11.

The diaphragm 16 is clamped in place by a cover plate 17, having an annular flange on its inner side to afford a chamber 18. The diaphragm 16 is in thrust relation with, but is not connected to, the member 12, carried by the diaphragm 11.

The port 7 leads to a chamber 19 into which is threaded, from the back of the body 5, a plug 20. This plug 20 is formed with an annular spring seat 21, for a spring 22, and the spring 22 tends to close a conical valve 23 which is guided in the plug 20 by means of a stem 24. The valve 23 seats at 25 in a passage leading from the chamber 19 to the chamber 10. It is axially aligned with the member 12 carried by the diaphragm 11 and when the diaphragm 11 is forced to the left, the valve 23 first closes the axial ort 14 in the member 12, and is then force from its seat 25.

The space between the diaphragms 11 and 16 is vented to atmosphere by means of the ports 26 so that when diaphragm 11 moves inward (i. e. to the left relatively to Fig. 1) it first closes an exhaust through the port 14 and then unseats the valve 23 to admit pressure fluid entering through the port 7. The reverse movement first seats the valve 23 to cut o' the supply and then opens the exhaust through the port 14.

whosecapacity is greater than the a justed approximatel capacity past-'the needleivalve 27. The leak,

port 30 1s controlled by a celluloid valve member 31, which is moved toward and from the leak port by a responsive element illustrated as a bi-metallicbar 32. This is adjustabl supported by means of the usual pivote, weighted saddle 33, and adjusting screw structure 34.

The recess 9 is connected by a port 35 with the chamber 10, which chamber.

The diaerential am of the diaphragme 11 thrust and 16 is so chosen with regard to the strength of the spring 22 and the .working pressure that the stress of the spring is neutralized .by the excess area of the iaphragm 16. Assuming that pressure .fluid is continuously supplied to the recess 6 and that the recess 9 is connected to themotor to be controlled, the operation of the device will readily be understood. The response of the thermostatic bar 32, in the case of a thermostat, so ad- 'usts the valve member 31 yrelatively to the eak port 30 as to establish a pressure in the controlling chamber 18. The intensity of this pressure is dependent upon the'condition of the thermostatic bar 32 and hence is a flmction of the atmospheric temperature. On an increase of pressure in the chamber 18, the diaphragm 16 will be forced to the left and w1ll tend to move member 12 and dia hragm 11 to the left a similar amount. uch movement .closes the exhaust port 14, if it be open, and opens the inlet valve 23 until a countervailing pressure is cre` ated in the controlled chamber 10 and in the connected motor. Similarly, a reduction of ressure in the chamber 18 allows the diaphragm 11 to move to the right un til 'a corres ending reduction of pressure in the cham r 10 has been caused by discharge through the ort 14. Consequently, the pressure 1n the c amber 10 follows the pressureA in the chamber 18 and because of thedierence in area of the diaphragm the pressure in the chamber 10 is a proximately the same as that in the cham r 18. This makes the entire supply ressure available and increases the range o utility of the dev1ce.

The v'alve 23 and its spring can readily be reinoved by unsere The' d'i'aphra may be rea y removed byv releasing an remo and the spacing hring dn-echen, and arr is the controlledY the plug 2u.

the cover platel'vh Since the diap structure is of the utmost simplici an access to all parte may readily be ad. p

What is claimed is: ,Y .1. A controldevicefcomprising imcombination a body ha va chamber, a pressure fluid inlet port eading thereto, and a port for connect' said chamberewith a evice to be contro ed; .a movablewall closing one side of said chamber land formed with an exhaust port leading through said wall'lto atmosphere; a valve1 contro said suppyport,s vur initsc pmgedgto be engaged by said movable wall, and when s engaged to close said exhaust ort and upon further inward movement ci) said wall to open said supply port; a second chamber having `a movable wall larger than ,and'in op relation w1th the movable w of the first chamber.; and a valve m responsive to changes in the medium to be controlled and serving to vary the pressure in said second chamber.

2. In an automatic controlling device, the combination of two parallel diaphr'atms of dierent areas in thrust relation wi each other; a casing for a controlling chamber in which pressure uid acts mst the larger diaphragm, and a contro ed chamber ada ted for connection with a controlled dbvice and in which pressurel fluid acts in the opposite direction against the smaller diaphragm, the space intervening between the dia hragms being o en to the atmosphere an the smaller diaphragm having an exhaust gort formed through it near its center; a va ve a to control the sup ly of pressure lui tothe contogether, the diap trolled dhamber, spring urged in its closing direction., and arranged lo be e a b the smaller diaphragm and whlb en)-y gzliged to close said exhaust port and u v n rther inward movement of said si;- phragm to open said. suppl port; and means responsive to the con 'tlon ofthe medium to be controlled for varying the pressure in said controlling chamber. 1

3. In an automatic controlling device, the combination of two parallel diaphra of hragms are not connected diierent areas in thrust relation' wit each other; a casin includm' g a y, a separator of dierent internal diameters on its op osite faces and a cover, the sma er diaphgm being' held against the relcetsls1 the dl 111115.' thelparatorrin an e argerl'ap sgm. ing held betvgveen the lseparator and the` cover, the space between the a .-n. beiniivnented to atmosphere .and the :m diap gm having a central vent rt leading therethrou h; a sup ly. vport ormed in thebodyand edm `saidman tralveiut` port; a combin -valve-guideandspringlfl seat threaded into said body and coaxial with said supply and vent ports; a spring seated in said seat; a valve urged in closing direction by said spring, gulded in said guide and arranged to close said supply and vent ports, individually and simultaneously in dierent positions of the smaller diaphragm; and valve means responsive to the condition of a medium to be controlled, arranged to Vary the pressure in the recess lf of said cover, and acting on said larger diaphragm.

In testimony whereof we have signed our names to this specication.

ARTHUR J. OTTO. CARL A. OTTO. 

